Editing Talk:2762: Diffraction Spikes

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::It's the sharp, angled edges that provide interference patterns (a set of "one-sided diffractions", rather than two-sided ones around an obstruction). A full round mirror on its own would not produce any spikes. Nor if the light from the edge areas cannot possibly reach the sensors, but that would mean less use of the mirror(s) they took great pains to send up there. And the secondary mirror ''has'' struts (in a Y-shape, I think, for technical reasons), thus why there's two minor spikes (actually six, but four are aligned to be hidden within the major spikes) as well as the hexagon-edge-induced set of six. Which also helps you understand in which orientation (or which two possibilities) the JWST was, in order to make any images you see from it.
 
::It's the sharp, angled edges that provide interference patterns (a set of "one-sided diffractions", rather than two-sided ones around an obstruction). A full round mirror on its own would not produce any spikes. Nor if the light from the edge areas cannot possibly reach the sensors, but that would mean less use of the mirror(s) they took great pains to send up there. And the secondary mirror ''has'' struts (in a Y-shape, I think, for technical reasons), thus why there's two minor spikes (actually six, but four are aligned to be hidden within the major spikes) as well as the hexagon-edge-induced set of six. Which also helps you understand in which orientation (or which two possibilities) the JWST was, in order to make any images you see from it.
 
::But this is already over-explained, really. You ''can'' design a mirror set to a avoid spikes, but with other technical compromises/etc. And above is correct, in that refractive telescopes can find themselves showing spikes (struts, if so designed, and other internal angles that may intrude into the light-path's edge). [[Special:Contributions/172.71.242.86|172.71.242.86]] 17:27, 13 April 2023 (UTC)
 
::But this is already over-explained, really. You ''can'' design a mirror set to a avoid spikes, but with other technical compromises/etc. And above is correct, in that refractive telescopes can find themselves showing spikes (struts, if so designed, and other internal angles that may intrude into the light-path's edge). [[Special:Contributions/172.71.242.86|172.71.242.86]] 17:27, 13 April 2023 (UTC)
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:Diffraction spikes are also caused by window screens, dirty or scratched windscreens, and other optical blemishes.  Given the relative scarcity of telescopes these are what most people have actually encountered.[[Special:Contributions/172.70.38.94|172.70.38.94]] 00:40, 15 April 2023 (UTC)
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The transcript is very long... Too long : as of now, 2055 characters. That "transcript" section is intended for people who can't see the image (blind people for example), so it should be almost as fast to read as it is for you to look at the comic. There is really no need the exact angles of the diffraction spikes or anything, just a description of what's happening so that we can get the joke. You should not try to write a vectorization of the image, there are automated tools for that. [[Special:Contributions/172.71.122.208|172.71.122.208]] 18:04, 13 April 2023 (UTC)
 
The transcript is very long... Too long : as of now, 2055 characters. That "transcript" section is intended for people who can't see the image (blind people for example), so it should be almost as fast to read as it is for you to look at the comic. There is really no need the exact angles of the diffraction spikes or anything, just a description of what's happening so that we can get the joke. You should not try to write a vectorization of the image, there are automated tools for that. [[Special:Contributions/172.71.122.208|172.71.122.208]] 18:04, 13 April 2023 (UTC)

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